feat(core): lightweight keys

packages/core/src/injectable.spec.ts

@@ -90,4 +90,10 @@ describe('injectable', () => {
     expect(result).toBe('override')
     expect(project).not.toHaveBeenCalled()
   })
+  it('stores key', () => {
+    const foo = injectable('foo', () => 123)
+    // $ExpectType "foo"
+    foo.key
+    expect(foo.key).toEqual('foo')
+  })
 })

packages/core/src/injectable.ts

@@ -32,10 +32,22 @@ export type Flatten<Tree> = Tree extends UnknownDependencyTree
       >
   : never
 
-export interface Injectable<Tree extends UnknownDependencyTree, Value> {
+export interface InjectableWithoutName<
+  Tree extends UnknownDependencyTree,
+  Value
+> {
+  (tree: Flatten<NoInfer<Tree>>): Value
+}
+
+export interface InjectableWithName<Tree extends UnknownDependencyTree, Value> {
   (tree: Flatten<NoInfer<Tree>>): Value
+  readonly key: Tree['name']
 }
 
+export type Injectable<Tree extends UnknownDependencyTree, Value> =
+  | InjectableWithoutName<Tree, Value>
+  | InjectableWithName<Tree, Value>
+
 export type InjectableValue<Target> = Target extends Injectable<
   UnknownDependencyTree,
   infer Value
@@ -59,7 +71,7 @@ type MapInjectablesToValues<Targets> = {
 }
 
 type MergeDependencies<
-  Inputs extends readonly Injectable<never, unknown>[],
+  Inputs extends readonly Injectable<UnknownDependencyTree, unknown>[],
   Name extends PropertyKey | never,
   Type
 > = {
@@ -73,12 +85,15 @@ type MergeDependencies<
 
 export function injectable<
   Name extends PropertyKey,
-  Inputs extends readonly Injectable<UnknownDependencyTree, unknown>[],
+  Inputs extends readonly (
+    | Injectable<UnknownDependencyTree, unknown>
+    | InjectableWithName<UnknownDependencyTree, unknown>
+  )[],
   Value
 >(
   name: Name,
   ...args: [...Inputs, (...values: MapInjectablesToValues<Inputs>) => Value]
-): Injectable<
+): InjectableWithName<
   {
     readonly [Key in keyof MergeDependencies<
       Inputs,
@@ -93,7 +108,7 @@ export function injectable<
   Value
 >(
   ...args: [...Inputs, (...values: MapInjectablesToValues<Inputs>) => Value]
-): Injectable<
+): InjectableWithoutName<
   {
     readonly [Key in keyof MergeDependencies<
       Inputs,
@@ -116,7 +131,7 @@ export function injectable(
   ] as never
 
   const memoizedProject = memoMany(project)
-  return (dependencies: Record<PropertyKey, unknown>) => {
+  const f = (dependencies: Record<PropertyKey, unknown>): unknown => {
     if (name !== undefined) {
       const override = dependencies[name]
       if (override !== undefined) {
@@ -126,6 +141,9 @@ export function injectable(
     const values = injectables.map((injectable) => injectable(dependencies))
     return memoizedProject(...values)
   }
+  f.key = name
+
+  return f
 }
 
 const isPropertyKey = (input: unknown): input is PropertyKey =>

packages/core/src/token.spec.ts

@@ -26,4 +26,10 @@ describe('token', () => {
     const result = foo({ [TOKEN_ACCESSOR_KEY]: accessor, foo: 'bar' })
     expect(cb).toHaveBeenCalledWith('bar')
   })
+  it('stores key', () => {
+    const foo = token('foo')<string>()
+    // $ExpectType "foo"
+    foo.key
+    expect(foo.key).toEqual('foo')
+  })
 })

packages/core/src/token.ts

@@ -1,4 +1,4 @@
-import { Injectable } from './injectable'
+import { InjectableWithName } from './injectable'
 
 export const TOKEN_ACCESSOR_KEY = '@injectable-ts/core//TOKEN_ACCESSOR'
 
@@ -10,7 +10,7 @@ export interface TokenAccessor {
 }
 
 export function token<Name extends PropertyKey>(name: Name) {
-  return <Type = never>(): Injectable<
+  return <Type = never>(): InjectableWithName<
     {
       readonly name: Name
       readonly type: Type
@@ -26,9 +26,15 @@ export function token<Name extends PropertyKey>(name: Name) {
     },
     Type
   > => {
-    return (dependencies) => {
+    const f = (
+      dependencies: {
+        readonly [TOKEN_ACCESSOR_KEY]?: TokenAccessor
+      } & Record<Name, Type>
+    ): Type => {
       const accessor = dependencies[TOKEN_ACCESSOR_KEY]
       return accessor ? accessor(dependencies, name) : dependencies[name]
     }
+    f.key = name
+    return f
   }
 }